Project Summary/Abstract: We propose to research and develop a novel, reliable, and affordable technology for effective sterilization of dental handpieces at room temperature. The Food and Drug Administration (FDA) recommends that these delicate instruments be heat-sterilized between patients to reduce the risk of disease transmission. While autoclaving is the most versatile of these methods, many materials and instruments suffer irreversible damage when exposed to moist heat at the temperatures and for the times required for sterilization. After several sterilization cycles, moist heat shortens the useful life of most dental tools. Moist heat sterilization rapidly corrodes metal instruments and dulls blades. The technology utilizes a non-corrosive gas sterilant produced in a non-thermal plasma source powered by a standard microwave oven magnetron to sterilize a wide range of materials and surfaces. The air/gas stream containing free radicals produced in the non- thermal plasma source will even be able to penetrate and efficiently sterilize instruments such as handpiece inner channels. The proposed sterilization technology is safe, will not require chemicals, and will be simple in operation and maintenance free. Its simplicity and affordability resulting from operating at low-moisture, low-temperature and with low energy requirements make it very suitable for developing a sterilization device for use in many dental offices. During preliminary tests, an air stream containing free radicals produced in the Pulsed Microwave Non-thermal Plasma (PMNP) system effectively inactivated 100% of highly concentrated microorganisms (107/ml) deposited on a Petri dish and killed 106 spores imbedded in a small paper disk with the temperature of the sterilization process maintained at~30oC. During Phase I of the program, preliminary material compatibility will be assessed and tests of sterilizing efficacy of dental reusable instruments including dental handpiece inner channels will be validated. Project Narrative: High quality care at lowest possible cost creates a necessity of development of new cheap sterilization technologies. Sterilization of Dental Handpieces (DHs) is currently 1 of the important issues in dental care, since these precision instruments, costing about $800.00 each, need to be sterilized between patients. The proposed development of the effective, room temperature sterilization technology offers a cheap alternative to autoclaving. [unreadable] [unreadable] [unreadable]